NOS inhibition sensitizes metaplastic breast cancer to PI3K inhibition and taxane therapy via c-JUN repression.

Metaplastic breast cancer (MpBC) is a highly chemoresistant subtype of breast cancer with no standardized therapy options. A clinical study in anthracycline-refractory MpBC patients suggested that nitric oxide synthase (NOS) inhibitor NG-monomethyl-l-arginine (L-NMMA) may augment anti-tumor efficacy of taxane. We report that NOS blockade potentiated response of human MpBC cell lines and tumors to phosphoinositide 3-kinase (PI3K) inhibitor alpelisib and taxane.

Synthesis of Pyrrolidine-2-ylidenes from Isoxazolines and Allenes.

A diastereoselective addition and rearrangement reaction has been developed for the synthesis of pyrrolidine-2-ylidenes from N-isoxazolines and electron-deficient allenes. This method proceeds via the rearrangement of a proposed -alkenylisoxazoline intermediate to generate densely functionalized pyrrolidine-2-ylidenes under simple catalyst-free conditions that tolerate ketone substituents and install relative stereochemistry at positions 3 and 4 of the heterocycle. Reaction optimization and the substrate scope are described in addition to studies evaluating the reactivity of the -dione and enaminone groups of the products.

TRAIL-induced cytokine production via NFKB2 pathway promotes neutrophil chemotaxis and immune suppression in triple negative breast cancers.

Tumor necrosis factor-related apoptosis-inducing ligand (TRAIL) is a potential cancer therapeutic that induces apoptosis in cancer cells while sparing the non-malignant cells in preclinical models. However, its efficacy in clinical trials has been limited, suggesting unknown modulatory mechanisms responsible for the lack of TRAIL activity in patients. Here, we hypothesized that TRAIL treatment elicits transcriptional changes in triple negative breast cancer (TNBC) cells that alter the immune milieu.

Students' Experiences with the Science and Engineering Practices in a Workshop-Based Undergraduate Research Experience.

This paper presents a phenomenographic investigation on students' experiences about research and poster presentations in a workshop-based undergraduate research experience with a focus on how the experience connects to the Science and Engineering Practices (SEPs) of the NRC and the principles of CUREs. This provides insight into how these structured research experiences reflect particular SEPs and also elements of scientific practice that are not captured in the SEPs as they have been formulated previously. This work showcases the importance of future applications, failure, and creativity as additional science practices necessary for students to engage in authentic science.

NOS2 and COX-2 Co-Expression Promotes Cancer Progression: A Potential Target for Developing Agents to Prevent or Treat Highly Aggressive Breast Cancer.

Nitric oxide (NO) and reactive nitrogen species (RNS) exert profound biological impacts dictated by their chemistry. Understanding their spatial distribution is essential for deciphering their roles in diverse biological processes. This review establishes a framework for the chemical biology of NO and RNS, exploring their dynamic reactions within the context of cancer.

Cyclization Reactions of In Situ-Generated Acyl Ketene with Ynones to Form Oxacycles.

Acyl ketenes react with polar unsaturated functional groups to give unique heterocyclic rings, yet reactions with unpolarized unsaturated functional groups have not been reported. Herein, we describe two effective ring-forming reactions between acetyl ketene and electron-deficient alkynes. The first reaction involves in situ tethering between acetyl ketene and nucleophile-containing 1,3-diynones, which promotes sequential intramolecular 1,6/1,4-additions to generate 2-methylene-2-pyrans in various yields (24-91%).

Spatial analysis of NOS2 and COX2 interaction with T-effector cells reveals immunosuppressive landscapes associated with poor outcome in ER- breast cancer patients.

Multiple immunosuppressive mechanisms exist in the tumor microenvironment that drive poor outcomes and decrease treatment efficacy. The co-expression of NOS2 and COX2 is a strong predictor of poor prognosis in ER- breast cancer and other malignancies. Together, they generate pro-oncogenic signals that drive metastasis, drug resistance, cancer stemness, and immune suppression.

NOS2 and COX2 Provide Key Spatial Targets that Determine Outcome in ER- Breast Cancer.

Estrogen receptor-negative (ER-) breast cancer is an aggressive breast cancer subtype with limited therapeutic options. Upregulated expression of both inducible nitric oxide synthase (NOS2) and cyclo-oxygenase (COX2) in breast tumors predicts poor clinical outcomes. Signaling molecules released by these enzymes activate oncogenic pathways, driving cancer stemness, metastasis, and immune suppression.

Intramolecular Carboxyamidation of Alkyne-Tethered O-Acylhydroxamates through Formation of Fe(III)-Nitrenoids.

We developed intramolecular carboxyamidations of alkyne-tethered O-acylhydroxamates followed by either thermally induced spontaneous or 4-(dimethylamino)pyridine-catalyzed O→O or O→N acyl group migration. Under iron-catalyzed conditions, the carboxyamidation products were generated in high yield from both Z-alkene and arene-tethered substrates. DFT calculations indicate that the iron-catalyzed carboxyamidation proceeds via a stepwise mechanism involving iron-imidyl radical cyclization followed by intramolecular acyloxy transfer from the iron center to the alkenyl radical center to furnish the cis-carboxyamidation product.

Pyruvate dehydrogenase operates as an intramolecular nitroxyl generator during macrophage metabolic reprogramming.

M1 macrophages enter a glycolytic state when endogenous nitric oxide (NO) reprograms mitochondrial metabolism by limiting aconitase 2 and pyruvate dehydrogenase (PDH) activity. Here, we provide evidence that NO targets the PDH complex by using lipoate to generate nitroxyl (HNO). PDH E2-associated lipoate is modified in NO-rich macrophages while the PDH E3 enzyme, also known as dihydrolipoamide dehydrogenase (DLD), is irreversibly inhibited.

Categorizing Student Learning about Research, Nature of Science, and Poster Presentation in a Workshop-Based Undergraduate Research Experience.

This article examines student experiences in a workshop-based undergraduate research experience studying the activity and inhibition of salivary amylase that provides students with the chance to participate in authentic scientific research prior to the start of their undergraduate studies, following the structure of a course-based undergraduate research experience (CURE). Understanding student experiences at this point in their studies is important because research experiences at the beginning of university studies have been shown to increase retention in STEM. This study utilizes meaningful learning and situated cognition as theoretical frameworks and phenomenography as a methodological framework, applied to data from semi-structured interviews with six students.

CoLab: A workshop-based undergraduate research experience for entering college students.

The goal of undergraduate chemistry laboratories is to allow students to learn about chemical systems and key laboratory skills. They should then apply this knowledge to solve problems and connect macroscopic observations in the laboratory with those occurring at the submicroscopic level. Unfortunately, these needs are not met through traditional confirmation labs.

Interferon-gamma is quintessential for NOS2 and COX2 expression in ER breast tumors that lead to poor outcome.

A strong correlation between NOS2 and COX2 tumor expression and poor clinical outcomes in ER breast cancer has been established. However, the mechanisms of tumor induction of these enzymes are unclear. Analysis of The Cancer Genome Atlas (TCGA) revealed correlations between NOS2 and COX2 expression and Th1 cytokines.

IL-27 induces an IFN-like signature in murine macrophages which in turn modulate colonic epithelium.

Mucosal delivery of IL-27 has been shown to have a therapeutic benefit in murine models of inflammatory bowel disease (IBD). The IL-27 effect was associated with phosphorylated STAT1 (pSTAT1), a product of IL27 receptor signaling, in bowel tissue. To determine whether IL-27 acted directly on colonic epithelium, murine colonoids and primary intact colonic crypts were shown to be unresponsive to IL-27 and to lack detectable IL-27 receptors.

Interferon-gamma is Quintessential for NOS2 and COX2 Expression in ER Breast Tumors that Lead to Poor Outcome.

A strong correlation between NOS2 and COX2 tumor expression and poor clinical outcomes in ER-breast cancer has been established. However, mechanisms of tumor induction of these enzymes are unclear. Analysis of The Cancer Genome Atlas (TCGA) revealed correlations between NOS2 and COX2 expression and Th1 cytokines.

New nitrosyl ruthenium complexes with combined activities for multiple cardiovascular disorders.

Nitrosyl ruthenium complexes are promising platforms for nitric oxide (NO) and nitroxyl (HNO) release, which exert their therapeutic application. In this context, we developed two polypyridinic compounds with the general formula -[Ru(NO)(bpy)(L)], where L is an imidazole derivative. These species were characterized by spectroscopic and electrochemical techniques, including XANES/EXAFS experiments, and further supported by DFT calculations.

Substituent and Solvent Effect Studies of N-Alkenylnitrone 4π Electrocyclizations.

The roles of substituent and solvent effects in promoting the 4π electrocyclization of N-alkenylnitrones to give azetidine nitrones have been investigated by experimental examination of relative rates, activation energies, and linear free energy relationships. These transformations are synthetically important because they favor the formation of a strained heterocyclic ring with imbedded functionality and stereochemical information for versatile derivatization. Mechanistic investigations, including Hammett studies, solvent-dependent Eyring studies, and solvent isotope effects, provide insight into the steric and electronic factors that control these electrocyclizations and identify trends that can be used to advance this approach towards the rapid synthesis of complex azetidines.

Chronic Exposure to Nitric Oxide Induces P53 Mutations and Malignant-like Features in Human Breast Epithelial Cells.

The small endogenous signaling molecule nitric oxide (NO) has been linked with chronic inflammation and cancer. The effects of NO are both concentration and temporally dependent; under some conditions, NO protects against damage caused by reactive oxygen species and activates P53 signaling. During chronic inflammation, NO causes DNA damage and inhibits repair proteins.

Cycloisomerization of Alkyne-Tethered N-Acyloxycarbamates to 2-(3H)Oxazolones through Nitrenoid-Mediated Carboxyamidation.

The cycloisomerization of alkyne-tethered N-benzoyloxycarbamates to 2-(3H)oxazolones is described. Two catalytic systems are tailored for intramolecular 5-exo-alkyne carboxyamidation and concomitant alkene isomerization. PtCl /CO (5 mol%, toluene, 100 °C) promotes both carboxyamidation and alkene isomerization but has a limited substrate scope.

Targeting Nitric Oxide: Say NO to Metastasis.

Utilizing targeted therapies capable of reducing cancer metastasis, targeting chemoresistant and self-renewing cancer stem cells, and augmenting the efficacy of systemic chemo/radiotherapies is vital to minimize cancer-associated mortality. Targeting nitric oxide synthase (NOS), a protein within the tumor microenvironment, has gained interest as a promising therapeutic strategy to reduce metastatic capacity and augment the efficacy of chemo/radiotherapies in various solid malignancies. Our review highlights the influence of nitric oxide (NO) in tumor progression and cancer metastasis, as well as promising preclinical studies that evaluated NOS inhibitors as anticancer therapies.

Systemic Nos2 Depletion and Cox inhibition limits TNBC disease progression and alters lymphoid cell spatial orientation and density.

Antitumor immune polarization is a key predictor of clinical outcomes to cancer therapy. An emerging concept influencing clinical outcome involves the spatial location of CD8 T cells, within the tumor. Our earlier work demonstrated immunosuppressive effects of NOS2 and COX2 tumor expression.

Synthesis, Characterization, and X-ray Crystallography, of the First Cyclohexadienyl Trifluoromethyl Metal Complex (η-CH)Fe(CO)CF.

Fluorochemistry is a field of tremendous developments and advances in several areas of science including materials, pharmaceuticals and agriculture. This makes the design and synthesis of fluorine-containing substances highly desirable research targets. The sub-area of synthetic perfluorinated chemistry proportionately attracts widespread interest by applying to all areas of chemistry including organic and inorganic.